Stencil paper for use in mimeographic printing (hereunder simply referred to as stencil paper) is generally made of paraffin-coated Japanese tissue paper or porous but strong Japanese paper coated with gelatin or collodion in castor oil. A stencil is made from the stencil paper by the stylus method, brush method or typewriting method. In accordance with the stylus method, the stylus is pressed against the surface of the stencil paper on a crosshatched steel plate to scrape the oily overcoat. In the brush method, a weakly acidic solution is applied on the gelatin-coated porous paper with a brush and the solution etches away the gelatin layer. In the typewriting method, a typewriter key is caused to impact the stencil paper and scrape selected portions of the oily overcoat. In each of these methods, preparation of stencil is manual and requires a substantial amount of time. Further, in accordance with these methods stencils cannot be made from photos or clippings of newspaper or magazines.
These defects can be eliminated by a discharge type automatic stencil maker. In such an automatic stencil maker, a drum around which the original and a sheet of paper are wound is rotated in order to read the original and simultaneously prepare a stencil. The stencil is prepared by scanning the original in a cylindrical form while a recording is made by discharge breakdown. Although the use of an automatic stencil maker eliminates defects inherent in the above methods, it causes new problems. For example, when a surface layer of the paper is removed by discharge breakdown, it creates a bad odor which pollutes the place where the machine is installed. Furthermore, the stylus used in the discharge breakdown recording must be frequently replaced.